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How climate change affects food-system resilience

Food systems interact with climate change in two key ways. First, they are a major driver of climate change, through their collective greenhouse gas (GHG) emissions. About a third of humanity’s GHG emissions are related to clearing land, growing food and feed, rearing livestock and dealing with their manure, and processing, cooking and transporting food.

Tim Benton, dean of Strategic Research Initiatives, University of Leeds, and distinguished visiting fellow, Chatham House

At the same time, our food system is horrendously inefficient: much food is lost or wasted, over-consumption is driving ill-health around the world, and the environment, in addition to our climate, is rapidly degrading. Focusing on making the food system efficient—by producing healthy and sustainable diets, with low waste—is increasingly necessary to live within planetary boundaries and avoid a growing human and planetary health crisis.

Second, food systems are impacted by climate change. As the climate changes, patterns of rainfall, heat and cold are changing, affecting the yields and suitability of crops in different places. In many places, especially in the tropics but also in some temperate areas, yields are likely to decline in line with climate change. Even in areas where yields may increase, the rising levels of CO2 in the atmosphere affect the way plants grow and may decrease the nutrient availability in the crops.

As the climate changes, extreme weather events will become more threatening. Increasing prevalence of heat and drought will be of particular importance to agriculture. Although a severe drought may especially be important locally (for farmers and food availability), such events can have impacts far beyond the area affected.

Food systems and their functioning

The food available in any one location is typically a mix of imported food and food produced more locally. Even with locally produced food, the inputs, the way it is farmed and the prices charged often depend on global markets and trade. This means events very far away can have localised impacts if their effects are transmitted through the market.

But crucially, the resilience of our global system has become more of a cause for concern through three interconnected drivers.

First, we have indeed become more interconnected with food, feed and inputs being traded further and in more complex ways. The world depends, for the majority of its calories, on a small handful of crops that underpin global diets: three crops provide half of the world’s calories (wheat, rice and maize) and a further five crops supply another quarter.

Second, as demand has grown for food and other goods, we have tried to produce goods as cheaply as possible. This has led to more land being used, as well as more intensively, and natural capital (like soils, water and biodiversity) being degraded. Our agricultural systems are under increasing pressure to produce more, whilst their ability to do so sustainably and in the face of shocks from the weather is declining.

Third, as we get more interconnected in space, we also get more interconnected across sectors. Food production is intrinsically dependent on other sectors, such as water, energy, transport, IT and communications. If energy becomes more expensive, or less available, it affects food production in myriad ways.

Cascading risks

As climate change increases the risk of extreme events, and as food systems become more interconnected and co-dependent, the potential for cascading and self-amplifying risks in the market increases. As figure one below shows, increasing pressure on the food system, coupled with co-dependence on other sectors, can make the system more fragile to shocks, especially from a changing climate. The reduction in food availability, or perception thereof, can cause self-amplifying effects through the market or policy responses driving up prices. Climate events do not have to be large to trigger a food-price spike, as we found in 2007-08 and 2010-11; they simply have to create the perception that food will be less available.

Figure 1: Rising vulnerability of food systems to shocks

Inevitably, as we look to the future, some climate events may be large (a mega-drought, a new Dust Bowl, the overturning circulation or changing configuration of the jet stream). We need to think more holistically to ensure that food systems can still function. Climate-smart agriculture is only part of the story.

ABOUT THE AUTHOR

Professor Tim Benton is the dean of Strategic Research Initiatives at the University of Leeds and distinguished visiting fellow at the Energy, Environment and Resources Department at Chatham House. During 2011-16 he was the “champion” of the UK’s Global Food Security programme, a multi-agency partnership of the UK’s public bodies (government departments, devolved governments and research councils) that undertook systemic analysis and horizon scanning of the challenges of providing sufficient, sustainable and nutritious diets for all. He has published over 150 academic papers, many of which focus on agricultural sustainability.